A multi-pronged attack designed to unravel the complexities of prostaglandin pharmacology and physiology in mammalian species (including man) is proposed. Studies over the past decade have firmly established the prostaglandins as significant intracellular metabolism regulators and as mediators of hormonal action. However, the intelligent use of PG's in clinical situations is hampered by our incomplete understanding of their physiological role and the wide- spectrum of pharmacological responses elicited. The proposed research includes conformational studies of the PG's and their diastereomers in connection with detailed structure-activity and receptor modeling. The other objectives of the research are essentially tools for delineating the control of prostaglandins in vivo. Prostaglandin metabolizing enzymes will be isolated by affinity chromatography and studied as to specificity of action. The enzymes isolated will be the basis of rapid microscale assays for prostaglandins. Finally, tethered prostaglandin agonists, prepared by novel tethering reactions related to those employed in preparing affinity chromatography phases, will be used to distinguish between physiological effects that require penetration of the cell and those that involve a receptor on the ourside of the cell membrane. The new drug and enzyme immobilizing methodoloy proposed, which produces linkages stable to hydrolysis (chemical and enzymatic), should be of wide applicability in other biochemical studies.